Boat-davit.



P. G. SANBORN dz W. A. HESSE.

BOAT DAVIT.

urmoumn rman DEO.8,1907.

9 1 5, 1 18, Patehted Mar. 16, 1 909.

3 sums-31mm 1.

ATTORNEY.

P. G. SANBORN & W. A. HESSB.

BOAT DAVIT.

APPLICATION rum) DEG.3,1907.

Patented Mar. 16, 1909.

3 SHEETS-SHEET 2. 47 33 P. G. SANBORN & W. A. HESSE.

BOAT DAVIT.

' APPLICATION nun mw.s,1907. 9 1 5 1 1 8 Patented Mar. 16, 1909. i a SHEETS-SHEET a.

WITNESS HVVENTORS,

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A TTORNEY.

1 at present, which can be operated present boats can be lowered.

sectional UNITED STATES PATENT orrron v PERCY G. SANBORN, OF SAN FRANCISCO, AN WALTERA. HESSE, OF ALAMEDA, CALIFORNIA.

, non'r-nnvrr.

Specification of Letters Patent.

Patented March 1 6, 1 909'.

Application filed. December 3, 1907. Serial No. 404,895.

To all whom it may concern:

Be it known that we, PERCY G. SANBORN and WALTER A. HESSE, citizens of the United States, residing, respectively, at San Fran- 'cisco, in the county of San Francisco, and

Alameda, in the county of Alameda, and State of California, have invented new and useful Improvements in Boat-Davits, of

which the fol-lowing is. a specification. Tlns invention relates to an improved boat davit, the object of the invention being to provide an apparatus of this character by means of which a boat can be lowered from a ship into the water much more ra idly than by a single person, instead of requiring, for a large boat, five or six men, as is at resent the case, and by which a boat can wlth certaint be low ered into the water on an even kee and the speed of descent'be under complete control.

A further important advanta e of this improvement is that it enables a oat to be lowered on the windward side of a well as on the leeward side, at which only at And a further advantage is that whereas in cold rev'erfy gions the lowering of the boat now requently entails long delay owing to the necessity of chopping away the ice which binds the lowering ro es by our apparatus this difficulty is entire eliminate r In t e accompanying drawings, Figure 1 is a front view of the apparatus in the position in which the boat is to be lowered in the water; Fig. 2 is an end View thereof; Fig. 3 is an enlarged longitudinal sectional view through the gear changing shaft; Fig. 4 is a front view view on the line, 5-5 of Fig. 1; Fig. 6 is. a broken horizontal section throu 11 the gearcasing; Fig; 7 is a broken view of t e same; Fig. 8 is a vertical section of the -base and gear casing, the gearing being shown in side elevation; Fig. 9 is a broken plan view of ends of the drums to show the clutch members; Fig. 10 is an enlarged horizontal section of the upper ends of the guide tubes; Fig. 11 is a vertical section through the brake ring on one of the drums.

Referring to the drawing, 1 indicates a hollow stand or base having a flange 2, by which it is bolted to and having a sleeve 4 dependin therefrom. Above said stand is a casing 5 w ich rotates on rollers 6, which in turn revolve u base 1;

vessel, as

of the same; Fig. 5 isan enlarged.

the leftis use the deck 3 of the vessel,

on the Through a central sleeve 7 epending from the casing passes a shaft 8 which also extends down through the sleeve 4, rollers 9 and 10 being interposed between said shaft and two sleeves 7 and 4 respectively. Upon said shaft 8 is secured a worm gear 11 driven by a worm 12 on a shaft 13 extending through'the wall of the stand and having a square outer end by which said shaft 13 can be turned by a suitable crank handle. By this means the casing can be rotated u n the stand. Since thewhole of the mechanism is su ported by said casing 5, it is by means of this worm and worm gear that said mechanism is rotated, to swing the boat from the position in which it hangs over the deck of the ship to a position proper to'lower it to the water.

Extending transversely through the casing projecting square 5 is a shaft 15 havin haft can be turned by ends 16 by which said s cranks applied thereto. Upon said shaft are v 18, rotatable with the bevel plnlons 17, shaft, but slidable thereon. The hub of each pinion is formed with a collar 19, and said collars are engaged by forks 20 secured to a slide'rod 21 which slides in bearings 22 carried by hangers 23, depending from the caslongitudinally by means of an arm 24 on a rock shaft 25 extending through the casing to the front thereof and having a crank handle 26. Said crank handle carries in its end a spring-actuated pin 27 which-is adapted to engage any one of three sockets, the middle socket 28 holding the crank handle in the position in which both bevel pinions are out of en agement, while the terminal sockets 29, ho d the crank handles in the osition in which either one bevel pinion or t e other 1s in operative engagement. are adapted to en shaftso32, 33. rear end a pinion 34 which meshes with a gear wheel 35 on a drum 36, and said ear wheel 35 likewise meshes with a gear w eel Said 'pinions age bevel gears 30, 31 on 37 on a drum 38, so that said drums 36, 38,

rotate in unison, but in opposite directions. When it is required to raise onl a comparatively light weight, as wl en t e boat is empty or nearl which directly drives the shaft 32, but when it is desired to impart a slow rotation to said drums, for a heavier load, the. rod 21 is shifted so that the bevel pinion 18 is thrown into engagement, which then rotates the shaft 33 on the right. This said rod being adapted to be moved so, the bev ji pinion 17 on T e shaft 32 carries at its shaft carries a pinion 40, which meshes with a gear wheel 41 on the shaft 32 so that, when the bevel pinion 18 is in mesh, the shaft 32 on the left is then driven more slowly than '5 before, and in consequencev the drums are more slowly rotated, but greater power is obtained. Wound around said drums are ropes 42, which pass upward to ether through a central vertical guide tu e 43 0 secured upon the casing, then around (pulleys 44 in a housing 45 at the top of sai guide tube and then within downwardly sloping ide tubes 46 leadin to points over the ends of the boat. In t e ends of said guide tubes 46 the ro es pass over pulleys 47 and thence tb suita le falls in the ends of the boat. When not in use, the-outer ends of the tubes 46, around the ropes, are stuffed with tow 48 or any suitable acking mate- 0 rial, toprevent the access 0 water to the tubes and-to the mechanism. Said guide arms both extend sufficiently out o the vertical central lon itudinal. plane of the casing of the contro ing mechanism to sup- 5'port said'boat at one side, out of contact with said mechanism, The ends of said tube 46'are additionall supported by struts or braces 49. It wi now be understood that by turning the crank handles on the ends of 0 the transverse shaft '15, one or the other of the two bevel pinions 17, 18 is rotated, therebyrotating, e1ther directly or indirectly, the "shaft 32 on the left, there y turning the two drums, in unison in opposite directions, so 5 that the ropes 42 are wound up together, and the boat is raised with absolute uniformity at both ends. 1

In order to lower the boat into the water, it is only necessamy'ito allow the drums to rotate by the weight of the boat so as to pay out the ropes42, while at the same time maintaining full control of said drums. For this purpose'there is provided a main brake comprising sleeves 50 adapted to engage the 5 drums, and a friction plate 51, apertured to pass over the hubs of the drums. Between said plate and the sleeves 50 are interposed owerful coiled springs 52. Said plate is orced inward toward said sleeves by means 0 of a screw 53 ada ted to be turned by a suitable crank hand e, the inner end of which screw abuts against the outer side of said plate. In order to prevent the brake sleeves 50 turning with the drums, the friction plate 5 51 is formed with two hub-like lateral projections 54 each of which and the corresponding tering teeth 55, and notches the teeth entering said notches, and preventing the turning of the brake sleeve, while at the same time permitting the'brake plate to be moved to and from the brake sleeve, this being accomlished by the screw 53 and springs 52.

hen said screw is screwed inward ressure is thereby imparted to the plate, an thence brake sleeve are formed with reg1s-' to the brake sleeves, the surfaces of which press against the brake drums. The pressure thereby obtained is of itself almost sufficient to prevent the descent of the boat. For instance, supposing the boat weighs 1000 pounds, .said main brake would create friction capable of holding, say, 900 pounds.

To support the residua weight of the boat there is provided an auxiliary brake, com prising a brake band 56 extending around a rake ring 57 surrounding the drum 36 on the left, and secured at its ends by plates 58,

to a lever 60 fulcrumed at 61 between the points of attachment of said plates. The end of said lever is de ressed by means of a cam 62 u ona rock s aft 63, to which rock shaft is a so attached an arm 64 carrying at its outer end a weight 65, so that said weight constantly tends to press said camu on said lever and thereby to tighten said bra e band about said brake ring, so that said ring is constantly under the control'of said brake, and the weight is such that, unless a lifting force is applhed thereto, the friction thereby created wi be sufficient, together with the friction caused by the main brake, to prevent the descent ofthe boat. Hence, the rate of descent can be controlled at all times by varying the amount of pressure that-is removed from the brake hand, this being controlled by means of a crank handle applied to the end of the shaft 63,and pressedin such a direction as 'to o pose the force of the weight 65. The braiie ring 57 is not fixedly secured to the drum 36, and checks the motion of said drum in one direction only, corresponding to the lowerin of the boat. A ratchet wheel is former on the drum 36,

and on the ring 57 are pivoted pawls 71, of

which there are here shown three in number, which engage the teeth of the ratchet wheel, so that the drum cannot rotate in'one direction without at the same time rotating the brake ring, whereas said drum can freely rotate in the other direction, corresponding to. the raising of the boat, without being affected by the action of said brake ring. This allows the full force of the brake to be kept on the brake ring, while raising the boat, so that, should the ower employed to raise the boat be removed then drop, but would be immediately arrested b said brake. be raise in perfect safety without any daner of. any sudden drop owing to the acciental diminution of the force which is so raising it. To lower the boat, first, the auxiliary weight is removed to a greater or less extent, as may be convenient, by exerting more or less force against the weight 65. Then the screw 53 is unscrewed until the main braking pressure is diminished to such a degree that the boat begins to drop. The,

or reduced, the boat could not 1 Hence the boat can Ill the shaft 63.

0 winding said ropes, and tally rotating said vertical guide tube,'sub-- arrested I y letting go of thecrank handle on We claim 1. In combination with a stand or base, a

tating the same thereon, a post secured upon said casing and having diverging arms arranged to guide ropes for supporting a boat,

drums in said casing on which sald ropes can for rotating said drums, an means for selectively operatin tially as descri ed.

In combination with casing tating a stand or base, a rotatable on said base, means for rethe same thereon, a drum within caslng, means for rotating saiddrum, a standard or post secured to said casing and rotatable therewith, and arranged to guide a rope for supporting a boat, a main brake for resisting the greater part of the load of the boat, an auxiliary brake arranged to resist the residual ortion of said wei 'ht, and means for varying the latter brake y hand, substantially as described.

3. Incombinationwith a stand or base, a I

casingrotatable on-said base, means'for rotating the same thereon, a post secured upon said casing and having diverging arms arranged to guide ropes for su porting a boat, drums in said casing on which said ropes can be wound, high and low s eed mechanisms for rotating said drums, and ively operating said mechanisms, comprising a crank handle, and connections whereby when said crank handle is moved to one limiting position one of said mechanisms is 0perative, when into another limiting position the other mechanism is operative,- and into an intermediate position both mechanisms are inoperative and means for retaining said crank handle in either ,one of the three positions in which it has been so, moved/sub.- stantially as described. V 4. In a boat davit, the combination of a central vertical ide tube, guide tubes extendin outwardfi from the upper end of the I centra tube, ulleys in said latter tubes, and at t the central guide tube, and braces or struts for said guide tubes, substantially as described.

' 5. In a boat suitable stand or base, an upwardly extending guide above said base, guide arms extending outwardly from the upper end of the ver-.

tical guide, said guides form conduits lowering a boat, drumsf being arranged to or winding and remeans for hOIlZOIlstantially as described.

6. In a boat suitable guides for ropesfor raising or lower- 5 ing a boat, a rope-wmding drum, means for be wound, high and low sgieed mechanisms said mechanisms substan-' means for selectguide 7 e points of connectlonwithdavit, the combination of a unwmdm to contain ropes for raising or davit, in combination with spring therebetween, substantially as described.

7. In a boat davit, the combination of suitable guides for ropes for raising and lowering a boat, drums for saidropes, means wherebysaid drums rotate in unison, means for winding said drums, and braking mechanism for said drums, comprising sleeves adapted to engage said drums, a friction plate, said sleeves and plate engaging parts whereby the sleeves are prevented turning with the drums, but said plate is movable to and from said sleeves, coiled sp s between said plate and sleeves, and mean s i br moving said plate toward said sleeves to compress said coil springs, substan-' tially as described.

8. In a boat davit the combination of suitable guides for ropes for raising and lowering a boat, drums for said ropes, means whereby said drums rotate in unison, means for Winding said drums, and braking mechanism for sald drums, comprising sleeves and plate being provided with co-engaging parts whereby the sleeves are prevented turning with the but said plate is movable to and from" said sleeves, coiled springs between said plate" and sleeves, and a screw for moving said sleeves to compress said coil springs, and a handle on the end ofsaid'screw, substantially as described.

9. Ina boat davit, the combination of suitable guides for guiding ropes for raising and lowering a boat, drums for winding, and unwinding said ropes, means for rotating said and a brake for one of saiddrums comprising a brake ring surrounding the rum, means whereby said brake ring is caused to rotate with the drum when the latter rotates in one direction, said drum eing inoperativeto rotate the brake ring when mo f in the other direction, a brake band for said brake rin and means for tightening said brake ban around said ring, su starliltially as described.

and lowering a boat, drums for winding and g said ropes, means for rotating said drums, and a brake for one of said drums. comprlsmg -a brake ring surrounding the means whereby ,said brake ring is caused to rotate with the drum when the a .boat davit, the combination of suitable guldesfor guiding ropes for raising being provided with 00-,

latter rotates'in one direction, said drum being inoperative to rotate the brake ring when mo -in'the otherdirection, a brake band for said brake rin and means for tightening said brake ban around said ring,

shaft, and a weight on &

ccmp'rising a lever to which the ends of the brake band are. attached at opposite sides of' its fulcrum, a rock shaft, means carried there on for rocking. said lever, an arm on said rock the free end bf said arm, substantially as described.

11. In a boat 'davit, the combination of a tubular uide for ropes for raising and lower-V fcr drawing in and paying out 'rdpes extending through said guides, substantially as described. i

In testimony whereof we have hereunto set our hands in the presence of two subscribing witnesses. v

- PERCY G. SANBORN.

.WALTER A. HESSE. Witnesses:

FRANCIS W. WRIGHT, D. B. RICHARDS. 

